Most modern automobiles are equipped with an ignition switch on the steering column which when locked, also locks the steering wheel and the transmission shift lever carried by the column thereby preventing unauthorized operation of the motor vehicle even if the engine is started without turning on the ignition switch, such as by so-called hot wiring or jumpering of the ignition switch. The steering and shift lever locks are normally engaged and released by movement of a rack mounted in the column and connected to the locks by wires. Normally, the rack is actuated by a pinion coupled to the ignition switch so that it is driven by manually turning the switch on and off. This rack and pinion, the ignition switch and a turn signal switch usually are all enclosed in a housing made of metal or plastic with relatively thin walls so that is has relatively low strength.
Thieves of motor vehicles have developed satisfactory tools and methods for either rapidly breaking this housing or rapidly engaging and pulling the ignition switch out of the steering column to thereby gain access to the rack so that it can be manually moved to unlock the steering wheel and shift lever, so that after the engine is started, the shift lever can be moved to engage the transmission and the vehicle can be steered and driven away under its own power. Replacement of the parts and repair of the damage caused by breaking this housing and pulling out the ignition switch is expensive and usually costs several hundred dollars.
Various protective guards for preventing unauthorized access to ignition switches in steering columns have been previously developed and one such protective guard is shown in U.S. Pat. No. 4,118,961 issued on Oct. 10, 1978. While this guard prevents unauthorized access to the ignition switch, it does not prevent the steering column housing from being broken to provide unauthorized access to the rack for releasing the steering wheel and shift lever locks so that the vehicle can be driven away under its own power.